How can plugs (such as USB) become smaller all the time, but also faster?

Question

I would expect more connections for it to become faster, so bigger plugs. But instead USB-C are much smaller than original USB (and SATA is much smaller than PATA, etc).

In: Technology

Answer 1

The old USB connectors are quite large because the were designed for computer and computer peripherals like printer, hard drives so the connector is designed to be robust, there are small enough compared to what they were connected to.

The computer had the Type-A that is still common on computers, USB chargers etc. Devices had a type-B that was a thicker and today you might find it on printers.

Later when there was interest to use in on small devices like phones the USB type-B mini was designed. It was a lot smaller and fit nicely on the devices of the day. So large enough to be tough and easy to manufacture but small enough for a phone of the day. This still used 4 wires as the previous but send data faster.

USB Type-B micro that is common today was designed because phones got thinner and thinner so a new standard was made so the USB connector did not limit the thickness. This uses the same 4 wire design and the initial large contact USB

The speed did not increase since the mini was introduced. There were faster USB micro standards that were approximate 3x as wide with 5 extra wires but is uncommon.

USB-C has a lot of improved feature. A huge change is a move from 4 to 24 wires and the increased speed is because extra wires is used at higher rates.

So USB has got smaller in size because of smaller devices. The size is more a question of how small connectors you can manufacture at low cost that is tough enough. So it is a mechanics and manufacturing limitation.

The data transfer rate depend on how fast and complex the chips that send and receive the data. USB is designed for low-cost devices so there is a need for the chips to be cheap. So the speed increase when semiconductor technology advances and you can build chips that are fast enough at reasonable cost and size.

So the interface speed is quite disconnected from the size of the connector.